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'UNITED STATES PATENT ()FFICEQ CARL RUMPFF, OF APRATH, NEAR ELBERFELD, PRUSSIA, GERMANY.

MANUFACTURE OF DYE-STUFF OR COLORING-MATTER.

SPECIFICATION forming part of Let ers Patent No. 256,376, dated April 11, 1882. Application filed January 9, 1882. (No specimens.)

To all whom it may concern Be it known that I, CARL RUMPFF, residing at Aprath, near Elberfeld, in the Kingdom of Prussia and Empire of Germany, have invented a new and useful Improvement in the Mannfacture of Dye-Stuffs or (Joloring-lVIattcrs of which the following is a specification.

My invention relates to a new dye-stuff which results from the reaction of diazo-alpha-naph thaline-monosulphonic acid with the soda salt of my alpha-monosulphonic acid of beta-naphthol.

The preparation and properties of my alphamonosulphonic acid of beta-naphthol, and also of its sodium salt, are described in my application for patent'filed April 8, 1881.

I prepare my new dye-stuff as follows: I dissolve one hundred kilograms of finely-powdered amido-alpha-naphthaline-monosulpho- I Die acid in one thousand liters of water. To this solution I add seventy-five kilogramsof hydrochloric acid of 21 Baum. 1 cool the mixture so prepared to from 3 centigrade to 6 centigrade, and then pour into it slowly a solution of twenty-five kilograms of sodium nitrite in one hundred kilograms of water. The mixture is now left at rest for several hours, when the desired chemical reaction will be completed -that is to say, the amido-alphanaphthaline-monosulphonic acid will be transformed into the diazo-alpha-naphthaline-monosulphonic acid. In the next operation I slowly pour the mixture containing the diazo-alpha- I Diazo-alphamaphthalin e monosulphonic sea Sodium salt of alpha monosulacid. phonic acid of beta-naphthol.

N i CIOHG E ggf -tm o1.

New coloring-matter.

The new dye-stuff is to be precipitated out ofits solution by common salt and purified by crystallization by water.

I claim-- As a new product, the dye-stuff or coloringmatter which results from the reaction ofdiazoalpha-naphthaline-monosulphonic acid with the solution of sodium salt of the alpha-mono-' sulphonic acid of beta-naphthol, substantially as described.

CARL RUMPFF.

Witnesses:

J. FERD. KEDENBURG, Fa. N. SCHULTER. 

